1. Field of the Invention
The present invention relates to an oligomerized organopolysiloxane cocondensate, which is optionally fluoro-functional, and soluble in water and/or alcohol, a process for producing the condensate, and a method of treating surfaces with the condensate.
2. Discussion of the Background
It is known that hydrophilic surfaces, especially ceramic, metallic, or glass surfaces can be hydrophobized by means of treatment with alkyl alkoxy silanes. Organosilanes which contain fluorine, with the general formula R'--Si(R").sub.3, with R' as a fluoridated organic radical and R" as a chlorine or alkoxy radical, find multiple uses for applying layers with both a hydrophobic and an oleophobic effect to surfaces. The coatings can also be used to apply dirt-repelling coatings to plate glass. The processes described are based on sol/gel processes, where micronized inorganic particles are used together with the fluoroalkyl silane. The application of such systems is technically complicated and mostly requires complex organic solvents and additives (see, for example, JA 07 112 126, JA 08 157 643, JA 08 026 774, JA 08 040 748, JA 07 232 399, JA 07 112 126, EP 0 658 525, JA 08 157 643, and EP 0 629 673).
Other complicated application methods, which produce intermediate layers on the substrate, are described in JA 07 238 229 and JA 07 138 047.
Significant amounts of organic solvents must be used in the production of oil-repelling and water-repelling coatings according to U.S. Pat. No. 5,424,130 (52 wt.-% ethanol), JA 07 289 985 (94 wt.-% isopropanol), and JA 07 257 943. Furthermore, processes are known which use ecologically undesirable solvents in significant amounts, for example chlorinated hydrocarbons or fluoro hydrocarbons (EP-A2 0 491 251 and EP-A2 0 493 747).
Some of the processes mentioned possess the disadvantage that after application of the coating agent, relatively high temperatures have to be applied in order to achieve the desired surface effect. The processes according to the German patent applications 196 49 953, 196 49 954, and 196 49 955 also require drying at temperatures &gt;100.degree. C. Various substrates, such as thermosensitive plastic surfaces, paper, furs, fabrics, or leather, are damaged at such high temperatures. Another disadvantage of the known systems and the older systems is that after they are acted on for an extended period of time by moisture, the desired surface effect is greatly reduced. This is expressed, for example, in the fact that glass plates which were treated with the system containing fluorine as described above and then had a strongly marked hydrophobic and oleophobic effect, demonstrate this effect only to a slight extent any longer after several hours of treatment in water (for example at the boiling temperature of water), or do not demonstrate it at all.
It was an important goal to develop silane-based systems which are soluble in an aqueous or an aqueous/alcoholic medium and which can be used to produce a hydrophobic and, if necessary, also an oleophobic coating on powdered, porous, or smooth flat or fiber substrates, using an easily performed impregnation process, at temperatures below 100.degree. C., advantageously at room temperature, where the effect does not significantly decrease even after the coating has been acted on for an extended period of time by moisture.
The German patent application 196 49 954 discloses a fluoroalkyl-functional composition containing organopolysiloxane, on a water/alcohol basis, which is obtained by
(a) mixing PA1 (b) mixing the mixture with water or a water/acid mixture and/or a water/acid/alcohol mixture, PA1 (c) adjusting the pH value of the reaction mixture to a value between 1 and 8. PA1 (a) mixing PA1 (b) mixing the mixture from above with water and with an acid, and, optionally, with an alcohol, PA1 (c) oligomerizing the cocondensate obtained in this way, thereby increasing the particle size. PA1 (a) mixing the components I described with the component(s) II and/or III and/or IV, in the molar ratio M as described above; PA1 (b) mixing the mixture from above with water and with an acid and, optionally, with an alcohol; and PA1 (c) oligomerizing the cocondensate obtained in this way, thereby increasing the particle size.
water-soluble organosilanes with the general Formula I EQU H.sub.2 N(CH.sub.2).sub.f (NH).sub.g (CH.sub.2).sub.h --Si(CH.sub.3).sub.z (OR).sub.3-z (I), PA2 where 0.ltoreq.f.ltoreq.6, g=0 if f=0 and g=1 if f&gt;1, 0.ltoreq.h.ltoreq.6, 0.ltoreq.z.ltoreq.1, and R is a linear, branched, or cyclic alkyl group with 1 to 8 C atoms or an aryl group, with fluoroalkyl-functional organosilanes with the general Formula II EQU R.sup.1 --Y.sub.m --(CH.sub.2).sub.2 Si(R.sup.2).sub.y (OR).sub.3-y (II), PA2 where R.sup.1 is a monofluoridated, oligofluoridated, or perfluoridated alkyl group with 1 to 9 C atoms or a monofluoridated, oligofluoridated, or perfluoridated aryl group, Y is a CH.sub.2, O, or S group, R.sup.2 is a linear, branched, or cyclic alkyl group with 1 to 8 C atoms or an aryl group, and R is a linear, branched, or cyclic alkyl group with 1 to 8 C atoms or an aryl group, 0.ltoreq.y.ltoreq.1, and m=0 or 1, and possibly organosilanes with the general Formula III EQU R.sup.3 --Si(CH.sub.3)(OR).sub.2 (III) PA2 and/or PA2 organosilanes with the general Formula IV EQU R.sup.3 --Si(OR).sub.3 (IV), PA2 where here and in the preceding formula, R.sup.3 is a linear, branched, or cyclic alkyl group with 1 to 8 C atoms, R.sup.3, here or in the preceding formula, is the same or different in each instance, R, here or in the preceding formula, is a linear, branched, or cyclic alkyl group with 1 to 8 C atoms or an aryl group, and R is the same or different, in each instance, in the molar ratio M=[a/(b+c+d)].gtoreq.0.1, with a&gt;0, b&gt;0, c&gt;0, d&gt;0, where a is the sum of the mole numbers of the organosilanes according to Formula I, b is the sum of the mole numbers of the organosilanes according to Formula II, and c, if applicable, is the sum of the mole numbers of the organosilanes according to Formula III, and d, if applicable, is the sum of the mole numbers of the organosilanes according to Formula IV, PA2 at least one water-soluble amino-functional organosilane with the general formula I EQU H.sub.2 N(CH.sub.2).sub.f (NH).sub.g (CH.sub.2)--Si(CH.sub.3).sub.z (OR).sub.3-z (I), PA2 where f is equal to 0 or a whole number from 1 to 6, g is equal to 0 if f is equal to 0, and g is equal to 1 if f is not equal to 0; h is a whole number from 1 to 6, z stands for 0, 1 or 2, and R is a linear, branched, or cyclic alkyl group with 1 to 8 C atoms or an aryl group, PA2 with at-least one fluoro-functional organosilane with the general Formula II EQU R.sup.1 --Y.sub.m --(CH.sub.2).sub.2 Si(R.sup.2).sub.y (OR).sub.3-y (II), PA2 where R.sup.1 is a monofluoridated, oligofluoridated, or perfluoridated alkyl group with 1 to 9 C atoms or a monofluoridated, oligofluoridated, or perfluoridated aryl group, Y is a --CH.sub.2 --, --O--, or --S-- group, R.sup.2 stands for a linear, branched, or cyclic alkyl group with 1 to 8 C atoms or an aryl group, R is a linear, branched, or cyclic alkyl group with 1 to 8 C atoms or an aryl group, and y stands for 0 or 1 and m for 0 or 1, and/or PA2 with at least one organosilane with the general Formula III EQU R.sup.3 --Si(CH.sub.3)(OR).sub.2 (III), PA2 and/or PA2 with at least one organosilane with the general Formula IV EQU R.sup.3 --Si(OR).sub.3 (IV), PA2 where in Formulas III and IV, R.sup.3, independently in each instance, is a linear, branched, or cyclic alkyl group with 1 to 8 C atoms, R, independently in each instance, is a linear, branched, or cyclic alkyl group with 1 to 8 C atoms or an aryl group, in a molar ratio M=[a/(b+c+d)].gtoreq.0.1, PA2 where a is the sum of the mole numbers of the organosilanes according to Formula 1, b, if applicable, is the sum of the mole numbers of the organosilanes according to Formula II, c, if applicable, is the sum of the mole numbers of the organosilanes according to Formula III, and d, if applicable, is the sum of the mole numbers of the organosilanes according to Formula IV;
It was not surprisingly found that the above task can be advantageously accomplished if the composition according to the German patent application 196 49 954 is modified, if necessary, with regard to the combination of the starting substances of the general Formula I to IV, and in any case by adding an additional process step.